The following is a tabulation of some prior art that presently appears relevant:
U.S. Pat. No.Issue DatePatentee208,797Oct. 8, 1878Craig1,054,754Mar. 4, 1913Dawley1,328,974Jan. 27, 1920Thompson2,239,727Apr. 29, 1941Mayer2,296,647Feb. 28, 1941McCormick3,019,735Feb. 6, 1962Moeller and Scarff3,185,040Apr. 15, 1965Ligon3,839,863Oct. 8, 1974Frazier3,853,036Dec. 10, 1974Eskridge et al.4,062,639Dec. 13, 1977Conlee4,087,205May 2, 1978Heintz4,477,234Oct. 16, 1984Roeder4,478,560Oct. 23, 1984Rupp5,036,667Aug. 6, 1991Thatcher6,431,046Aug. 13, 2002Okpokowuruk
This invention pertains to piston to piston reciprocating devices commonly used in pumps and engines. In this invention and the prior art reciprocating motion is achieved with the use of a pilot valve and a fluid input control valve. The fluid input control valve alternates the fluid in pressure between the two sides of the drive piston. As the drive piston nears the end of its motion the pilot valve is actuated which in turn switches the fluid input control valves thus reversing the motion of the drive piston achieving reciprocating motion. The drive piston is mechanically connected to an output piston which provides an output fluid at a different flow rate and pressure than that of the input fluid. As can be seen in the above referenced patents there are many way to interconnect these components.
The previous state of the art has resulted in devices                a) designed for narrow specific applications,        b) that are bulky,        c) that are complicated and difficult to manufacture,        d) with valves that either wear out quickly or tend to leak,        e) that are difficult to miniaturize, and        f) that have a relatively low maximum operating speed.        